scholarly journals Finger-jointing of green Eucalyptus globulus L. wood with one-component polyurethane adhesives

2021 ◽  
Author(s):  
Oscar González-Prieto ◽  
José Manuel Casas Mirás ◽  
Luis Ortiz Torres
Keyword(s):  
Eucalyptus Globulus ◽  
Bending Strength ◽  
Strength Properties ◽  
Raw Material ◽  
Green Wood ◽  
Finger Joints ◽  
Polyurethane Adhesives ◽  
Cold Setting ◽  
Finger Jointing ◽  
Glued Joints

AbstractThe use of glued finger joint in green wood, directly from the sawing process, would open the possibility to obtain glued timber from small-sized wood, achieving an efficient use of the original raw material. The gluing of finger-jointed green wood, with moisture content above the fibre saturation point, may improve the efficiency and the manufacturing process of glulam or joinery. This may be especially beneficial for a hardwood such as Eucalyptus globulus L., which is a globally important forest resource, but is a challenging wood to dry. This article presents a study on the possibility to develop finger joints with wood in green state. To compare them, conventional finger joints on dry wood and solid boards without end joints were also manufactured. Cold-setting and fast-curing commercial one-component polyurethane adhesive systems were used. Finger-jointed samples were tested to determine mean and characteristic values (5th percentile) of density, bending strength and modulus of elasticity, and the results were analysed and discussed. Green-glued joints showed no statistically significant differences compared to the solid boards and improved strength properties with respect to dry-glued joints.

ANALISA SIFAT KETEGUHAN PATAH DAN TEKAN BETON SEMEN DARI TULANG ROTAN

2014 ◽  
Vol 6 (2) ◽  
pp. 7
Author(s):  
Djoko Purwanto
Keyword(s):  
Bending Strength ◽  
Strength Properties ◽  
Raw Material ◽  
Research Purpose ◽  
Cement Concrete ◽  
Concrete Frame ◽  
Concrete Building ◽  
Concrete Materials ◽  
Research Show

Indonesia has the potential of rattan is  enough large, but the value of the sale and utilization is still limited as materials for baskets, furniture,  handicrafts and so on. This research purpose to obtain bending and compressure strength properties when the rattan used for substitution  of iron materaial making to  cement concrete building simple houses. The raw material of used for research this is rattan has done processing (preservation and drying). Cement concrete frame made of rattan and molds for casting. Concrete frame rattan incorporated in the mold and filled dough (cement: gravel: sand = 1: 2: 3 plus water as needed). Treatment was observed that the diameter rattan (A) which includes: 8 mm (a1), 10 mm (a2) and 12 mm (a3); and the distance between the iron ring (B) which includes 11 cm (b1); 15 cm (b2); and 19 cm (b3). The number of repeat 3 times. Parameters observed bending and compressure strength.The results of the research rattan diameter 8-12 mm and the distance ring iron 11-19 cm produces bending strength from 18.24 to 40.13 kg /cm2 lower than cement concrete from iron materials (95.76 to 120.36 kg / cm2); and compressure strength from 28.33 to 42.85 kg/cm2 larger                                         than from iron cement concrete materials (20 to 34.67kg/cm2). The results of the research show  bending strength from rattan lower and compressure sterngth than big concrete from iron.Keywords: rattan, cement concrete, bending strength, compressure strength

Influence of Composition and Isothermal Sintering on the Properties of Hydroxyapatite Bioceramic Bodies

2014 ◽  
Vol 979 ◽  
pp. 347-350
Author(s):  
Rungsarit Koonawoot ◽  
Cherdsak Saelee ◽  
Sakdiphon Thiensem ◽  
Sittiporn Punyanitya
Keyword(s):  
High Efficiency ◽  
Bending Strength ◽  
Strength Properties ◽  
Raw Material ◽  
Dihydrogen Phosphate ◽  
Ammonium Dihydrogen Phosphate ◽  
Mass Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

This work reports the influence of chemical composition and sintering schedule on the properties of sintered bodies of hydroxyapatite (HA) bioceramic. The method of preparing sintered bodies by solid state reaction and uniaxial pressing. The raw material used calcium carbonate (CaCO3) and ammonium dihydrogen phosphate (NH4H2PO4) powder as precursors. These powders were mixed at CaCO3: NH4H2PO4 mass ratio of 1:0.697, 1:0.692, 1:0.689, 1:0.685 and 1:0.68, respectively. The compositions in the temperatures range of 800-1300 °C for 3 hour. The sintered bodies were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), and Fourier transform infrared spectroscopy (FTIR). Properties including phase, microstructures, porosity and bending strength of the samples. The results show that green bodies can be sintered at 1150 °C for 3 hours. This temperature found that crystals growth, highest of HA phase content in sintered bodies, good density and high efficiency strength properties.

scholarly journals Optimization of Laccase/Mediator System (LMS) Stage Applied in Fractionation of Eucalyptus globulus

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 731
Author(s):  
Javier M. Loaiza ◽  
Ascensión Alfaro ◽  
Francisco López ◽  
María T. García ◽  
Juan C. García
Keyword(s):  
Eucalyptus Globulus ◽  
Solid Phase ◽  
Liquid Fraction ◽  
Strength Properties ◽  
Raw Material ◽  
Eucalyptus Wood ◽  
Mediator System ◽  
Laccase Mediator System ◽  
Alkaline Delignification ◽  
Enzymatic Delignification

In a biorefinery framework, a laccase/mediator system treatment following autohydrolysis was carried out for eucalyptus wood prior to soda-anthraquinone pulping. The enzymatic and autohydrolysis conditions, with a view to maximizing the extraction of hemicelluloses while preserving the integrity of glucan, were optimized. Secondly, pulping of solid phase from Eucalyptus globulus wood autohydrolysis and the enzymatic process was carried out and compared with a conventional soda-anthraquinone (AQ) pulping process. The prehydrolysis and enzymatic delignification of the raw material prior to the delignification with soda- Anthraquinone (AQ) results in paper sheets with a lower kappa number and brightness and strength properties close to conventional soda-AQ paper and a liquid fraction rich in hemicellulose compounds that can be used in additional ways. The advantage of this biorefinery scheme is that it requires a lower concentration of chemical reagents, and lower operating times and temperature in the alkaline delignification stage, which represents an economic and environmental improvement over the conventional process.

scholarly journals Effect of bending pattern on finger joint bending strength

2012 ◽  
pp. 73-80
Author(s):  
Igor Dzincic ◽  
Tanja Palija ◽  
Dragan Pavlovic
Keyword(s):  
Bending Strength ◽  
Beech Wood ◽  
Finger Joint ◽  
Experimental Results ◽  
Limited Information ◽  
Beam Length ◽  
Finger Joints ◽  
Joint Influence ◽  
The Face ◽  
Finger Jointing

Limited information is available on end gluing hardwoods in contrast to softwoods, which have been extensively investigated. The objective of this study was to examine the influence of bending patern on bending strength of finger jointed beech wood. In structural uses finger jointing is finally the major method to end joint timber for the production of glue-laminated elements. There are no bending strength experimental results for finger-jointed hardwoods for investigations conducted in Serbia. Two finger jointed profiles were studied in accordance with DIN68140. The finger joints were made by side and by face of beam. Length jointed samples were loaded at the side and in the face. The obtained results led to the conclusion that the direction of load, gluing surface and the position of joint influence on the strength of continued longitudinal beams.

scholarly journals Density, hardness and strength properties of densified fir and aspen woods pretreated with water repellents

Holzforschung ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Hüseyin Pelit ◽  
Fatih Emiroglu
Keyword(s):  
Compression Ratio ◽  
Bending Strength ◽  
Linseed Oil ◽  
Vacuum Treatment ◽  
Strength Properties ◽  
Aspen Wood ◽  
Positive Effect ◽  
Water Repellents ◽  
Impregnated Wood ◽  
Compression Temperature

AbstractIn this study, the effect of thermo-mechanical densification on the density, hardness, compression strength, bending strength (MOR), and modulus of elasticity (MOE) of fir and aspen wood pretreated with water repellents was analyzed. Wood specimens were impregnated with paraffin, linseed oil and styrene after pre-vacuum treatment. Then, the impregnated wood specimens were densified with compression ratios of 20 and 40%, and at 120, 150 and 180 °C. The results indicated that the density, hardness and strength properties of the all densified specimens (untreated and impregnated) increased depending on the compression ratio and temperature. For all tested properties, higher increases were obtained in the paraffin and styrene pretreated specimens compared to untreated samples. However, the increase rates in linseed oil pretreated specimens were generally lower than untreated specimens. Regarding water repellents the most successful results in all tested properties were determined in styrene pretreated specimens. The density, hardness and strength properties of all specimens increased with the increase in compression ratio. On the other hand, the increase in the compression temperature negatively affects the properties of untreated and linseed oil pretreated specimens, while having a generally positive effect on the properties of paraffin pretreated specimens. However, all tested properties of styrene pretreated specimens have increased significantly due to the increase in compression temperature. The increasing strength properties of wood as a result of densification have increased much more with paraffin and especially styrene pretreatment. These combinations can be considered as an important potential for applications that require more hardness and strength.

Comparative Study on Mechanical Strength Properties of Concrete by Using Demolished Concrete Waste

2019 ◽  
Vol 1 (6) ◽  
pp. 235-239
Author(s):  
Sabarinathan K ◽  
Ashwathi R
Keyword(s):  
Comparative Study ◽  
Mechanical Strength ◽  
Coarse Aggregate ◽  
Environmental Awareness ◽  
Strength Properties ◽  
Raw Material ◽  
Construction Waste ◽  
The World ◽  
Day By Day

The growing environmental awareness and Construction waste, is increasing day by day which in turn makes the world in seeking for examining the characteristics of Construction waste and obtaining a solution by using its reliable segments such that it can be used as a raw material and Conservation the natural recourses like Coarse aggregate

Albizia richardiana King & Prain as a raw material for ply and particleboard

2015 ◽  
Vol 22 (3) ◽  
pp. 139-141
Author(s):  
Md. Rahaman ◽  
Khurshid Akhter ◽  
S. Hossain ◽  
Md. Islam
Keyword(s):  
Bending Strength ◽  
Urea Formaldehyde ◽  
Physical And Mechanical Properties ◽  
Solid Content ◽  
Raw Material ◽  
Standard Specification ◽  
Press Temperature ◽  
Albizia Richardiana ◽  
German Standard ◽  
Press Time

Woods of Albizia richardiana has been studied for assessing the suitability for plywood and particleboard manufacture. It was found that 1.5 mm thick smooth and figured veneer can be peeled and dried easily. Three-ply plywood were made using veneer of this species bonded with liquid urea formaldehyde glue of 50% solid content extended with wheat flour and catalyzed (ammonium chloride) with 2% hardener under the three specific pressures, viz,1.05 N/mm2, 1.40 N/mm2, 1.76 N/mm2 in three replications at 6 minute press time and 120°C press temperature. Dry and wet shear test were conducted on the sample and their shear load at failure per unit area and percentage of wood failure were determined. 1.05 N/mm2 pressure for the manufacture of plywood was found to be the best. The physical and mechanical properties of Albizia richardiana wood particleboard were studied. The particleboards were tested for determining the strength and dimensional stability. The tensile strength 0.56N/mm2 passed the British and German standard specification, bending strength (modulus of rupture10.80N/mm2) was found nearest to Indian Standard but low German and British standard specification.

Study on Particleboard made from Nipa palm (Nypa fruticans) stem wood and Rajkoroi (Albizia richardiana) wood

2018 ◽  
Vol 25 (1) ◽  
pp. 15-18
Author(s):  
Md. Mahabubur Rahaman ◽  
◽  
Khurshid Akhter ◽  
S. Hossain ◽  
Md. Rakibul Islam ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Dimensional Stability ◽  
Bending Strength ◽  
Strength Properties ◽  
Wood Chips ◽  
Standard Specification ◽  
Stem Wood ◽  
Nypa Fruticans ◽  
Albizia Richardiana ◽  
Nipa Palm

The study was conducted to find out the suitability of making particleboard using nipa palm (Nypa fruticans) stem wood and rajkoroi (Albizia richardiana) wood chips. Particleboards were fabricated at six different ratios of nipa palm stem and rajkoroi wood chips such as 100:0, 75:25, 50:50, 25:75, 10:90 and 0:100. Characteristics of particleboards such as modulus of rupture, internal bond strength, water absorption, thickness swelling and moisture content were measured. Results shows that particleboards made from 100% rajkoroi wood chips have the highest static bending properties and highest tensile strength properties of other particleboards but 100% nipa palm stem wood chips have the lowest static bending and lowest tensile strength properties of other particleboards. 10% nipa palm stem wood chips particleboard have the highest bending strength and tensile strength is better than 100% nipa palm stem wood chips and other mixing chips of particleboards. Mechanical, water resistance and dimensional stability properties were tested according to Indian standard specification. Tensile strength passed the British and German standard specification and nearest to Bureau of Indian Standard, bending strength was found nearest to Indian Standard but lower than German and British Standard specification. Strength property of rajkoroi wood chips particleboard is higher than nipa palm steam wood chips particleboard but dimensional stability is lower than nipa palm steam wood chips particleboard.

scholarly journals Chemical characteristics and Kraft pulping of tension wood from Eucalyptus globulus labill

2012 ◽  
Vol 36 (6) ◽  
pp. 1163-1172 ◽  
Author(s):  
María Graciela Aguayo ◽  
Regis Teixeira Mendonça ◽  
Paulina Martínez ◽  
Jaime Rodríguez ◽  
Miguel Pereira
Keyword(s):  
Eucalyptus Globulus ◽  
Lignin Content ◽  
Strength Properties ◽  
Kraft Pulping ◽  
Pulp Yield ◽  
Chemical Characteristics ◽  
Kraft Pulps ◽  
Opposite Wood ◽  
Alkali Consumption ◽  
Pulp Strength

Tension (TW) and opposite wood (OW) of Eucalyptus globulus trees were analyzed for its chemical characteristics and Kraft pulp production. Lignin content was 16% lower and contained 32% more syringyl units in TW than in OW. The increase in syringyl units favoured the formation of β-O-4 bonds that was also higher in TW than in OW (84% vs. 64%, respectively). The effect of these wood features was evaluated in the production of Kraft pulps from both types of wood. At kappa number 16, Kraft pulps obtained from TW demanded less active alkali in delignification and presented slightly higher or similar pulp yield than pulps made with OW. Fiber length, coarseness and intrinsic viscosity were also higher in tension than in opposite pulps. When pulps where refined to 30°SR, TW pulps needed 18% more revolutions in the PFI mill to achieve the same beating degree than OW pulps. Strength properties (tensile, tear and burst indexes) were slightly higher or similar in tension as compared with opposite wood pulps. After an OD0(EO)D1 bleaching sequence, both pulps achieved up to 89% ISO brightness. Bleached pulps from TW presented higher viscosity and low amount of hexenuronic acids than pulps from OW. Results showed that TW presented high xylans and low lignin content that caused a decrease in alkali consumption, increase pulp strength properties and similar bleaching performance as compared with pulps from OW.

Sign in / Sign up

Export Citation Format

Share Document